A conventional tool box is shown in FIG. 1 and includes a base 100 and a cover 200 which is connected to the base 100 by a snap device 201. The base 100 has a plurality of recesses defined therein for receiving tools and bits therein. When using the tools or the bits, the user opens the cover 200 and picks the tool and the bit. The conventional tool box simply provides a function for retaining the tools and the bits. The bits are cooperated with a tool which occupies a lot of space and in order to receive the tool in the tool box, the tool box has to be made large enough. However, the large tool box is inconvenient for transportation and storage. A bit box is then developed and receives bits and engaging parts only. Although the bit box collects the variety of bits so that the user can choose the bits to be used and receives the bits in a bit box, a tool such as a ratchet tool is still carried with the user. In other words, there still needs a box to receive the ratchet tool.
The present invention intends to provide an improved tool box which retains a lot of bits and can engage a bit and is used as a tool. Accordingly, the tool box has two functions one of which is to receive bits therein and the other function is to engage a bit in an engaging hole defined in the outside of the tool box and used as a tool screwdriver.